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Health condition

Auditory neuropathy spectrum disorder, from ABR diagnosis to cochlear implants and OTOF gene therapy.

A hearing disorder where the cochlea works but the signal reaching the brain is desynchronised. UK-based, multidisciplinary care makes a real difference at every age.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against BSA, NHSP, NICE and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects current UK practice including cochlear implantation criteria and the first OTOF gene therapy trials.

Key facts

ANSD at a glance.

The essentials, in plain English, so families and adults can ask better questions at the audiology and ENT clinic.

  • What it is

    A hearing disorder where outer hair cells function normally but neural transmission to the auditory brainstem is disrupted or desynchronised.

  • Signature pattern

    Present otoacoustic emissions or cochlear microphonic on ABR, alongside an absent or grossly abnormal auditory brainstem response.

  • How common

    Roughly 10 to 15 per cent of children with permanent hearing loss, with higher rates among NICU graduates.

  • Speech in noise

    Poor speech discrimination out of proportion to the audiogram is the day-to-day hallmark of ANSD.

  • Biggest single gene

    OTOF (otoferlin) accounts for the largest share of genetic cases and now has targeted gene therapy in trial.

  • Managed by a team

    Audiology, ENT, paediatrics, neurology, genetics and speech and language therapy work together from the outset.

Why this guide matters

A different kind of hearing loss, with different answers.

ANSD sits alongside sensorineural hearing loss but behaves very differently. The three points below shape everything else on this page.

  • The audiogram can mislead

    Pure-tone thresholds can look reassuring while speech understanding is severely affected. Speech-in-noise testing tells the real story.

  • Cochlear implants often help

    Where hearing aids give limited benefit and the cochlear nerve is present, implantation frequently transforms listening and language outcomes.

  • OTOF gene therapy is now real

    For biallelic OTOF-related ANSD, AAV gene therapy trials are open in the UK, Europe, US and China, with early results that were unthinkable a decade ago.

How the diagnosis is made

From screening flag to a full picture.

The steps a UK audiology and ENT team will normally follow, in order, so families and adults know what to expect and why.

  1. 01

    Assessing

    Newborn hearing screening flag

    A baby who passes OAEs but is referred on ABR, or shows an atypical ABR, needs urgent NHSP audiology referral to consider ANSD.

  2. 02

    Assessing

    Detailed history and risk review

    Prematurity, low birthweight, hyperbilirubinaemia, hypoxia, ototoxic drugs, meningitis, head injury and family history all matter.

  3. 03

    Assessing

    Diagnostic ABR with rarefaction and condensation

    The tell-tale finding is a preserved cochlear microphonic with an absent or grossly abnormal neural response, ideally confirmed on repeat testing.

  4. 04

    Confirming

    OAEs, tympanometry and acoustic reflexes

    OAEs are usually present, tympanometry is typically normal and stapedial reflexes are almost always absent.

  5. 05

    Confirming

    Behavioural audiometry and speech in noise

    Age-appropriate pure-tone and speech testing quantifies real-world hearing, which can range from near-normal to profound.

  6. 06

    Confirming

    MRI of brain, internal auditory canals and cochlear nerve

    Rules out cochlear nerve hypoplasia or aplasia, brainstem lesions and other neurological causes that change management.

  7. 07

    Preparing

    Genetics, neurology and ophthalmology workup

    Hearing loss gene panel including OTOF, plus nerve conduction studies and eye review to screen for CMT, Friedreich ataxia and mitochondrial disease.

Typical timeline: from screening flag to a settled plan in weeks, with genetics running alongside.

Symptoms

What ANSD actually looks like.

A picture that swings from near-normal audiograms to profound loss, with the day-to-day difficulty focused on clarity in noise.

  • Fluctuating thresholds

    Hearing can vary day to day or hour to hour, which is unusual in typical sensorineural hearing loss.

  • Poor speech discrimination

    Difficulty understanding words is much worse than the audiogram alone would predict.

  • Struggles in background noise

    Classrooms, restaurants and family gatherings are disproportionately hard, even with mild loss on paper.

  • Delayed speech and language

    Babies and toddlers may be quiet, mispronounce words or fall behind expected milestones without a clear reason.

  • Inconsistent responses to sound

    Carers often describe a child who sometimes hears well and sometimes seems to ignore speech entirely.

  • Normal or near-normal audiogram

    Some people with ANSD have pure-tone thresholds within normal limits yet still cannot follow conversation.

  • Adult-onset presentation

    Adults may present with slowly progressive hearing difficulty linked to an underlying peripheral or mitochondrial neuropathy.

  • Red flag - NICU history plus screening fail

    A preterm baby with jaundice or hypoxia who refers on ABR should be assessed for ANSD without delay.

Treatment

How ANSD is treated in the UK.

Access first, then devices, then, where appropriate, cochlear implantation or OTOF gene therapy. Language support runs alongside every step.

  • Hearing aid trial

    A structured trial is usually offered, but benefit can be limited because the problem is neural timing, not simple loudness.

  • Remote microphone and FM systems

    Radio-aid systems in the classroom and at home lift the speech signal above background noise, which is often the biggest daily win.

  • Cochlear implantation

    Considered for children and adults with poor hearing aid benefit, particularly where the cochlear nerve is present and severe-to-profound loss is confirmed.

  • OTOF gene therapy

    AAV-based therapies such as DB-OTO, OTOF-GT and the CHOP trial are recruiting infants and children with biallelic OTOF mutations, with early results showing substantial hearing gains.

  • Speech, language and auditory-verbal therapy

    Intensive early therapy supports listening, spoken language and confidence, and works alongside any device or sign-language approach.

  • Sign language and total communication

    BSL and total communication give reliable access to language while listening is being optimised, and are actively supported by families and Deaf education services.

  • Neonatal prevention

    Timely phototherapy and, where needed, exchange transfusion for severe hyperbilirubinaemia prevent a major non-genetic cause of ANSD.

  • Underlying condition management

    Where CMT, Friedreich ataxia, mitochondrial disease or immune-mediated neuropathy is found, treating the systemic condition can change the hearing trajectory.

Specialist centres and support

Where UK families and adults are seen.

Great Ormond Street, the Nottingham Auditory Implant Programme, Manchester, Bradford, Cambridge and Newcastle all run established ANSD and cochlear implant services. The National Deaf Children’s Society, the Ear Foundation and BSHAA offer family and adult support that runs alongside NHS care.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, specialist society standards and published trial data, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your audiologist, ENT surgeon, geneticist or paediatrician knows your history and can tell you which parts apply to you or your child. If in doubt, get seen.

  • British Society of Audiology (BSA). Practice guidance on auditory neuropathy spectrum disorder.

  • NHS Newborn Hearing Screening Programme (NHSP). ABR testing protocols and referral pathways.

  • NICE. Cochlear implants for children and adults with severe to profound deafness (TA566).

  • Regeneron, Otogenix/Lilly and CHOP. Published early-phase results of AAV-OTOF gene therapy trials, 2024 to 2025.

Red flags

When ANSD needs urgent attention.

Most ANSD is managed in scheduled multidisciplinary clinics. These are the situations that need faster action or a specialist opinion.

  • NICU graduate who refers on ABR

    Preterm babies with jaundice, hypoxia or ventilation histories are at high risk and need urgent audiology follow-up.

  • Kernicterus or severe hyperbilirubinaemia

    Any baby who has crossed exchange transfusion thresholds should be assessed formally for ANSD, even after treatment.

  • Family history of hearing loss or neuropathy

    A pattern of hearing loss, CMT or Friedreich ataxia in relatives raises the pretest probability of a genetic ANSD.

  • Discrepancy between audiogram and speech understanding

    When a person cannot follow speech despite reasonable pure-tone thresholds, ANSD should be considered explicitly.

  • Progressive difficulty in a young adult

    Slowly worsening speech-in-noise trouble in a teenager or young adult warrants ABR, imaging and neurology input.

  • Cochlear nerve hypoplasia on MRI

    A small or absent cochlear nerve changes cochlear implant candidacy and requires specialist implant-centre review.

  • New neurological signs

    Ataxia, foot deformity, weakness or vision change alongside hearing loss point to a systemic neuropathy that needs workup.

  • Sudden or fluctuating adult onset

    Rapid changes may reflect immune-mediated or metabolic causes and should prompt urgent referral, not watchful waiting.

  • Suspected OTOF-related ANSD

    Confirmed biallelic OTOF mutations open the door to gene therapy trials and should trigger a specialist centre discussion.

Living with it

A condition that rewards early, joined-up care.

Four things that make the biggest difference day to day for people with ANSD and the families around them.

A quiet reminder

Language is time-sensitive, decisions are not one-off.

Get language input in early, keep reviewing what is working, and know that the plan can and should evolve as the child grows and evidence changes.

  1. 01 Access

    Get the sound to the ear

    Remote microphones and good classroom acoustics often help more than raw amplification, particularly in noise.

  2. 02 Language

    Do not wait for a single answer

    Start language input early through listening, sign or both, so a child never has to catch up while decisions are being made.

  3. 03 Review

    Reassess regularly

    ANSD can fluctuate and change over time, so hearing, speech and school performance need scheduled reviews.

  4. 04 Community

    Lean on specialist support

    NDCS, the Ear Foundation, BSHAA and specialist implant centres offer families and adults practical, emotional and educational support.

Frequently asked

Everything we get asked about ANSD.

Quick answers on diagnosis, hearing aids, cochlear implants and the new OTOF gene therapy trials.

  • What is auditory neuropathy spectrum disorder?

    ANSD is a hearing disorder where the cochlea, and specifically the outer hair cells, works normally but the auditory nerve does not transmit sound to the brainstem in a synchronised way. That is why otoacoustic emissions or the cochlear microphonic are present while the auditory brainstem response is absent or grossly abnormal.

  • How is ANSD different from ordinary sensorineural hearing loss?

    In typical sensorineural loss, the cochlea is damaged and both OAEs and the ABR are usually reduced or absent in a matching pattern. In ANSD the cochlea appears to work but the neural signal is disrupted, which is why speech clarity and hearing in noise are often much worse than the audiogram suggests.

  • What causes ANSD?

    Causes fall into genetic and non-genetic groups. Genetic causes include OTOF, PJVK, CDH23, MPZ, PMP22, TMEM43, mitochondrial disorders and syndromic conditions such as Charcot-Marie-Tooth, Friedreich ataxia, Wolfram and Refsum. Non-genetic causes include severe neonatal jaundice with kernicterus, prematurity, very low birthweight, hypoxia, ototoxic drugs, meningitis, head injury and immune-mediated disease.

  • How is ANSD diagnosed in babies and children?

    The pattern is usually picked up through newborn hearing screening, where a baby passes OAEs but is referred or shows an atypical ABR. Diagnosis is then confirmed with a full diagnostic ABR looking for the cochlear microphonic, along with tympanometry, acoustic reflexes, behavioural audiometry when the child is old enough, MRI of the brain and cochlear nerve, and genetic and neurology assessment.

  • Do hearing aids and cochlear implants work in ANSD?

    Hearing aids are trialled but can be less helpful than in typical hearing loss because loudness alone does not fix neural timing. Cochlear implants are often considered when hearing aids do not give enough benefit and the cochlear nerve is present on MRI. Outcomes are frequently excellent, particularly for OTOF-related ANSD, where the implant bypasses the synaptic problem in the inner hair cells.

  • Is there gene therapy for ANSD?

    Yes, for one specific cause. AAV-based gene therapies targeting OTOF, including DB-OTO from Regeneron, OTOF-GT from Otogenix and Lilly, and the CHOP gene therapy trial, are recruiting infants and children with biallelic OTOF mutations. Early results reported in 2024 and 2025 show partial to near-normal hearing restoration in landmark cases. Gene therapy for other genetic causes of ANSD is still at earlier research stages.

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